Mithod of producing formed metallic articles



. UNITED STATES PATENT OFFICE.

I CHARLES L. GEBAUEB, 0F CLEVELAND, OHIO.

METHOD OF PRODUCING FORMED METALLIC ARTICLES.

1V0 Drawing.

jects the provision of a new method whereby.

the production of certain classes of articles out of known, common, and fusible metals can be facilitated, and whereby articles of use can be made out of metallic substances which hitherto could be worked by no known method. 1

The essence of my invention consists in this that the metal in finely divided condition is compacted by great pressure into the substantial or exact size and shape of the article desired, after which it is brought to an elevated temperature less than its melting point and maintained at that temperature for a considerable time. As a result of this treatment the particles cohere together in a solid, rigid, integral, homogeneous Whole, which whole bears the finished shape and size without necessitg of machining or forming operations. urthermore articles made in this way are generally more dense than if made by casting processes, while several metals can be treated thus which from their infusibility can not be cast or from their hardness can not be machined after casting. a

In my former Patent No. 1,223,322 granted April 17, 1917 and in my former applications Nos. 113,313 and 169,176, filed Aug. 5 1916, and May 17, 1917, respectively I have described articles made by compacting together two or more distinct metals of different fusing points and heating the same to a temperature intermediate their several fusing points, which I formerly supposed was essential to success, but I have discovered that a solid rigid homogeneous article can be produced by compacting to the desired shape eithera finely divided single metal or finely divided mixture of metals and by suitably heat treating the same at a temperature less than that of fusion of the single metal in the first case or less than that of any of the metals in the second case.

This invention is of use for a great 'many Specification 1mm 2mm. Pat t No ,1

' Application filed October 16, 1918. Serial No. 258,402.

purposes in the arts and sciences; for example in the construction of electrodes for vacuum tubes; in the production of all manner of tungsten or molybdenum articles for electrical, chemical, mechanical or metallurgical uses; for the manufacture of dies,

bearings, small parts, intricate patterns, etc., in iron, nickel, chromium, vanadium, titanium, or the alloys of same or, like metals; or in mixtures of titanium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel and the like as in making compound substances for special purposes to take the place of the expensive casting, forging, and machining.

As one example of my improved process and of an article made therefrom I may make a valve part out of iron reduced byhfydrogen, compressed hydraulically to the s apedesired under a pressure of, e. 9., 2,000 pounds per square inch, and raised to a'dull red heat (6. 800 C.) and maintained at that temperature for about one hour.

As another example I make puppet valves for internal combustidn engines by compacting iron, nickel, tungsten and chromium into a mold under a pressure of 4,000 pounds per square'inch and afterward maintain ing the same at a temperature of about 1200 C. for about half an hour.

As another example of my improved method I make tools and dies by compacting into a suitable mold a mixture of. iron, molybdenum and chromium under a pressure of 1,000 pounds per square inch and thereafter heating the same for about one hour to a temperature of about 1200 C. In each .of the above cases I preferably employ a preponderance of iron with about 10% of chromium, the balance consisting of the remaining ingredients named.

If the mixture be first compacted under sufficient pressure I find that little or no change in shape or size will take place during the succeeding heat treatment. My invention is characterized by compacting together the pure metals in finely divided form to the ultimate shape required and subsequently treating them to a temperature greater than their critical temperature but 'less than the melting point of any of them.

By critical temperature I mean the lowesttemperature at which molecular rearrange ment of the material becomes possible.

This temperature varies very greatly for different substances, as is well known, where- 

